The present invention relates to the field of aligning optical components, notably optical coupling elements, to optical waveguides.
A high optical coupling efficiency between a photonic chip—or photonic integrated circuit (PIC)—and an optical element is a key requirement in the optical industry. Positioning errors may lead to sub-optimal coupling and therefore to optical loss which impair the overall system performances.
U.S. Pat. No. 7,415,184 discloses an arrangement for providing optical coupling into and out of a relatively thin silicon waveguide, formed in the SOI (silicon-on-insulator) layer of a SOI layer stack and including a lens element and one defined reference surface within the SOI layer stack for providing optical coupling. However, no passive lateral coupling can be realized because no vertical reference surfaces are available. Thus, a need remains in art for an efficient arrangement for coupling optical signals between waveguides and another optical element.